Aquatic herbs with parallel-veined leaves and diclinous fls. on a slender-stalked spadix. Perianth regular, 3 to 6-parted, the inner segments petaloid. Stamens 3 to 12. Ovary adherent to the perianth, 1 to 9-celled, with 3. 6 or 9 large stigmas.

Fruit dry or succulent, many-seeded, indehisent. Seeds without albumen.

Genera 12. species 20. native of fresh water in Eurepe, N. America, E. Indies and N. Holland. They appear to possess no active properties.

1. LIMNO'BIUM, Richard. Frogs-bit. (Gr.Order CXXXVI Hydrocharidaceae Frogbits 1941 a lake, Order CXXXVI Hydrocharidaceae Frogbits 1942 life.) Flowers monoecious, arising from subsessile spathes; Order CXXXVI Hydrocharidaceae Frogbits 1943 spathe. 1-leaved, about 3-flowered, calyx 3-sepaled, corolla 3-petaled, petals oblong-linear; stamens 6 to 12, monadelphous; Order CXXXVI Hydrocharidaceae Frogbits 1944 spathe 2-leaved, 1-flowered; calyx and corolla as in the Order CXXXVI Hydrocharidaceae Frogbits 1945 ; stamens 6, subulate rudiments; ovary 6 or 9-celled, becoming a co-seeded berry. - Order CXXXVI Hydrocharidaceae Frogbits 1946 Herb acaulescent, in stagnant waters, multiplying by 6tolons, and with floating lvs. Fls. showy, white, the Order CXXXVI Hydrocharidaceae Frogbits 1947 on long stalks.

L. Spongia Rich. - In Braddock's Bay, L. Ontario (Sartwell); scarce at the north, common in the south, E. Ky.! to Ga. (Feay) and La. (Hale). Lvs on long petioles, roundish, obtuse or broadly acute, often cordate, 1' to 18" diam. Ped. of the sterile fls. slender, about 3' long, of the fertile, thick, about 1' long, both kinds either together on the same stalk or on different stalks which are connected by the stolons (Dr. Feay). The leaves beneath are purplish and spongy with large cells. Jl., Aug. (Hydrocharis, Bosc. H. cordifoiia Nutt.)

2. ANACH'ARIS, Richard. Ditch Moss. (Gr. av, an indefinite particle,Order CXXXVI Hydrocharidaceae Frogbits 1948 uncomely.) Flowers polygamous, solitary, from a tubular, bifid, axillary spathe; perianth 6-parted, colored; Order CXXXVI Hydrocharidaceae Frogbits 1949 minute, with 9 oval, nearly sessile anthers; Order CXXXVI Hydrocharidaceae Frogbits 1950 perianth excessively produced into a filiform tube above the ovary, limb 6-parted, stamens 3 to 6, often abortive; style capillary; adherent to the tube of the perianth; stigmas 3, large; fruit few-seeded. Order CXXXVI Hydrocharidaceae Frogbits 1951 Small aquatic herbs, with submersed pellucid opposite or verticillate lvs.

A. Canadensis Planchon. Lvs. verticillate in 3s and 4s, lanceolate, oblong or linear surrulate; stig. 2-lobed. - Resembling a coarse moss, in still waters and bogs. St. filiform, diffusely dichotomous, very leafy. Lvs. 3 to 6" by (less than) 1", thin and diaphanous, sessile, obtuse. Fls. minute, of a dingy white, the slender, hair-like tube 2 to 10' long, according to the depth of the waters. Stigmas recurved between the segments, crested with glandular hairs. Aug. (Udora, Nutt.)

3. VALLISNE'RIA, Micheli. Eel-grass. (In honor of Anthony Vallisner, a French botanist.) FlowersOrder CXXXVI Hydrocharidaceae Frogbits 1952Order CXXXVI Hydrocharidaceae Frogbits 1953 ; spathe ovate, 2 to 4-parted. Order CXXXVI Hydrocharidaceae Frogbits 1954 Spadix covered with minute flowers, enclosed in a 3-parted spathe; corolla 0. Order CXXXVI Hydrocharidaceae Frogbits 1955 Spathe bifid, 1-flowered; perianth elongated; sepals linear; stigmas 3, ovate, bifid; fruit elongated, cylindrical, many-seeded. - Order CXXXVI Hydrocharidaceae Frogbits 1956 Submersed. Lvs. all radical, grass-like. Scape spiral, very long.

V. spiralis L. Lvs. linear, obtuse, serrulate at the end, tapering at the base, floating. - A curious plant, in slow moving or stagnant waters, IT. S. Leaves linear, 1 - 2f long, about 1/2' wide, the edges thinner than the middle. Scapes several, of the sterile plants short, of the fertile plants very tortuous, 2 - 4f long when extended, thread-like, thickened at the top, bearing each a single, white flower at or near the surface. Sepals and petals crowning the (1') long, narrow, incurved ovary, which, is half concealed in the spathe. Jl, Aug. (V. Amer-icana Mx.)